Free age calculator. Enter your date of birth to get your exact age in years, months and days, plus total days lived, day of week born and next-birthday countdown.
Your results will appear here.
Enter your values and press Calculate.
Age is counted in completed years first: subtract the birth year from the as-of year, then subtract one if this year's birthday has not happened yet. From that last birthday, whole calendar months are counted, and the leftover days are the remainder. Leap years are handled automatically because real calendar dates are used — a 29 February birthday is observed on 28 February in non-leap years. Leave the “as of” date blank to calculate your age today, or set any past or future date (useful for exam cut-offs or historical ages).
Use it as a quick age finder: enter any date of birth and get the full breakdown instantly.
How do I calculate my exact age? Count completed years first: subtract the birth year from the as-of year, then subtract one if this year's birthday hasn't happened yet. From that last birthday, count whole calendar months, and the leftover days are the remainder — giving age in years, months and days.
Worked example: born 15 May 1990, as of 21 October 2026. Completed years: 36. From 15 May 2026 to 21 October 2026 is 5 whole months plus 6 days — so the exact age is 36 years, 5 months and 6 days, or 13,308 days old. The day before a birthday (e.g. 14 May 2026) the age is still 35 years, 11 months and 29 days — the year only flips on the birthday itself. To calculate age manually, follow those three steps; leap years are handled automatically because real calendar dates are used.
This age calculator also reports your total days lived — 13,308 days for someone born 15 May 1990 as of 21 October 2026. How many days old am I right now? Enter your date of birth with the as-of date blank and the calculator uses today.
Decimal age expresses the same age as a single number: 36 years and 159 days is about 36.45 years — used in medical growth charts and actuarial tables. Milestones make the numbers fun: 10,000 days old is a bigger party than most birthdays, and 1 billion seconds lands around age 31.7.
Leave the as-of date blank for how old am I today, or set any date to calculate age on a specific date. School and exam cut-offs work this way: was a child born 3 March 2020 old enough for a 1 September 2026 cut-off? Set the as-of date to the cut-off and read the exact age.
Historical questions work too: how old would a historical person be today, or what was someone's age at death — enter the death date as the as-of date. Future dates are fine as well: how old will I be in 2030 is just your birth date against 1 January 2030. Someone born in 2000 is 26 for most of 2026.
Every result includes the weekday of your birth — 15 May 1990 was a Tuesday. Knowing what day of the week you were born settles family debates and helps when old records only give a weekday. The calculation uses the proleptic Gregorian calendar, which is what every modern date library assumes.
The countdown shows how many days until your next birthday — 206 days for a 15 May birthday as seen from 21 October. A birthday that falls today reads 0 and the age has already incremented. Dates like 29 February are observed on 28 February in non-leap years, matching the most common convention.
What is Korean age? In the traditional Korean system you are 1 at birth and gain a year every New Year, so you can be 1–2 years older than your international age. (South Korea officially switched to international age for legal purposes in 2023.) Chronological age is the standard Western count used here — completed years since birth. How is age calculated in different countries? Most of the world uses completed years; a few East Asian traditions historically counted differently, but official documents everywhere now use the international system.
How to calculate age in Excel? The DATEDIF age formula does it without a calculator: =DATEDIF(birth_date, TODAY(), "Y") gives completed years, "YM" gives the leftover months, and "MD" the leftover days. Combine them: =DATEDIF(A1,TODAY(),"Y")&" years, "&DATEDIF(A1,TODAY(),"YM")&" months, "&DATEDIF(A1,TODAY(),"MD")&" days". DATEDIF is undocumented but works in every modern Excel — this page uses the same three-part logic internally.
Is my date of birth stored or sent anywhere? No. The calculation runs entirely in your browser — no account, no server, nothing transmitted or logged. You can even use it offline once the page has loaded.
Subtract the birth year from the current year, subtract one if your birthday hasn't occurred yet this year, then count whole months and leftover days from your last birthday. Or enter your date of birth above — the calculator does all three steps instantly.
Yes. It uses real calendar dates, so leap years — including the extra 29 February — are counted exactly in both the year/month/day breakdown and the total days lived.
Your birthday is observed on 28 February in non-leap years, the most common convention. Someone born 29 February 2000 is 26 years, 7 months and 23 days old on 21 October 2026.
No. Everything is computed locally in your browser; no data is sent to any server, stored, or logged.
The traditional Korean system counts you as 1 at birth and adds a year each New Year, making you 1–2 years older than your international (chronological) age. South Korea adopted international age for legal matters in 2023.
Your age in completed years since birth — the standard international system this calculator uses.
Yes — set the as-of date to any future date. Useful for how old will I be in 2030, retirement planning, or checking a future eligibility cut-off.
Calculate each person's age as of the same date and subtract, or subtract the two birth dates directly — the total-days figure makes the difference exact to the day.
The result panel shows it automatically — for example, 15 May 1990 was a Tuesday.
Years: current year minus birth year (minus one if the birthday hasn't happened). Months: whole months since the last birthday. Days: the remainder. Leap years fall out naturally from real calendar dates.
Use =DATEDIF(birth_date, TODAY(), "Y") for years, "YM" for leftover months and "MD" for leftover days. DATEDIF is undocumented but works in all modern Excel versions.
Some age calculators show a live ticking counter that keeps moving every second to dramatize your exact age. Ours doesn't — it computes a fixed, exact age for the date you choose, so there's nothing running in the background.
Yes — a free online age calculator with no sign-up, and your date of birth never leaves your browser.